Buffer solutions with the component concentrations shown below were prepared. Which of them should have the highest pH? A) [H₂PO₄^-] = 0.50 M, [HPO₄^2-] = 0.50 M B) [H₂PO₄^-] = 1.0 M, [HPO₄^2-] = 1.0 M C) [H₂PO₄^-] = 1.0 M, [HPO₄²^-] = 0.50 M D) [H₂PO₄^-] = 0.50 M, [HPO₄^2-] = 1.0 M E) [H₂PO₄^-] = 0.75 M, [HPO₄^2-] = 1.0 M

Question

Quizplus · Accepted Answer

The highest pH is achieved when the concentration of the conjugate base ([HPO₄²⁻]) is greater than the concentration of the acid ([H₂PO₄⁻]). In option D, [HPO₄²⁻] is 1.0 M and [H₂PO₄⁻] is 0.50 M, which results in a higher pH.

Buffer Solutions with the Component Concentrations Shown Below Were Prepared